Biological Evaluation of Marine Protected Area: Evidence of Crowding Effect on a Protected Population of Queen Conch in the Caribbean |
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| Authors: | Christophe Béné & Alexander Tewfik |
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| Institution: | CEMARE, University of Portsmouth, Locksway Road, Southsea PO4 8JF U.K. ;Department of Biology, McGill University, 1205 Ave Dr. Penfield, Montreal, H3A 1B1 Canada. |
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| Abstract: | Abstract This study provides a first evaluation of the biological impact of a marine fishery reserve on the stock of queen conch (Strombus gigas) in the Turks and Caicos Islands. The density and the shell length of the population living in the reserve are compared with those of the individuals living in the surrounding fished areas. The results show that the adult density is six times higher in the reserve than in the fished areas. The shell length analysis shows that both adults and juveniles are significantly smaller in the reserve than in the fished area. This unexpected result suggests the existence of a crowding effect (i. e. a high density‐induced reduction in growth rate) within the reserve. It is hypothesised that this crowding effect is due to the superimposition of two factors leading to very high density values in the reserve: (a) the reduced fishing mortality following the creation of the reserve, (b) the existence of natural barriers that impede the emigration of adults outside the reserve. These results are then discussed in relation to current considerations on marine fisheries reserves. |
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| Keywords: | Density-dependent growth rate spillover effect Turks and Caicos Islands marine reserves Caribbean gastropods |
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